CO２浓度和温度升高对11种植物叶片解剖特征的影响

以生长在严格控制的温度梯度，以及温度和CO2浓度梯度2个温室里的8种美国中西部弃耕地常见草本植物和3种美国东部落叶阔叶林优势木本植物为材料，通过比较叶片栅栏组织厚度、海绵组织厚度、和叶片总厚度的变化，探讨CO2浓度和温度升高对不同功能型植物叶解剖特征的影响。结果表明：当温度升高时，C4植物的叶片厚度增加，而C3植物叶片厚度的变化无明显规律；当CO2浓度升高时，9种C3植物中有7种植物的叶片总厚度增加，而C4植物叶片厚度减少。植物叶片解剖特征沿CO2浓度和温度梯度呈现线性和曲线变化趋势；不同物种的同一组织厚度和同一物种的不同组织厚度，对温度和CO2都升高或仅仅温度升高的反应都存在很大的差异。在未来全球变化情况下，植物叶片对CO2和温度升高的反应存在明显的种类差异。由于植物的结构和功能是相关联的，这种解剖结构的改变将可能引起植物功能上对CO2和温度升高反应的差异。

Interactive effects of elevated CO2 and temperature on the leaf anatomical characteristics of eleven species

The leaf anatomical features of 11 species grown in two greenhouses with strictly controlled temperature gradients and temperature CO_2 gradients was studied. The palisade parenchyma thickness, the spongy parenchyma thickness and the total leaf thickness were studied and analyzed with the purpose of demonstrating the effect of elevated CO_2 and temperature on the leaf anatomical characteristics. The results show that with the increase of temperature, the leaf thickness of C_4 species increases while the leaf thickness of C_3 species shows no constant changes; with the increase of CO_2, seven out of nine C_3 species increase their total leaf thickness, while the C_4 species decrease their leaf thickness. As for the change-trend on the multi-grades, plants exhibit linear or curve change. With the increase of temperature or both temperature and CO_2, on the 11 chosen species, different plants, even different branches in one plant, the leaf thickness varies greatly. These facts illustrate that the effect of increasing CO_2 and temperature on plants is species-specific. Since plant structures are correlated with their functions, the changes in anatomical leaf characteristics due to the elevated temperature and CO_2 may lead to functional differences.